diff --git a/build.gradle b/build.gradle
index a41412bcec..65ad224725 100644
--- a/build.gradle
+++ b/build.gradle
@@ -321,6 +321,83 @@ tasks.register("installDefaultGems") {
     doLast {
         rake(projectDir, buildDir, 'plugin:install-default')
     }
+    finalizedBy "syncStdlibBouncyCastleJars"
+}
+
+tasks.register("syncStdlibBouncyCastleJars") {
+    description = "Replace JRuby stdlib BouncyCastle jars with the version from the bundled jruby-openssl gem"
+    doLast {
+        def bundleDir = file("${projectDir}/vendor/bundle/jruby")
+        def stdlibDir = file("${projectDir}/vendor/jruby/lib/ruby/stdlib")
+
+        // Find the bundled jruby-openssl gem (search all Ruby compat version dirs)
+        def gemDirs = []
+        bundleDir.eachDirRecurse { dir ->
+            if (dir.name.matches("jruby-openssl-.*-java") && dir.parentFile.name == "gems") {
+                gemDirs.add(dir)
+            }
+        }
+        if (gemDirs.isEmpty()) {
+            throw new GradleException("Cannot find bundled jruby-openssl gem in ${bundleDir}")
+        }
+        def gemDir = gemDirs.sort().last()
+
+        // Read BC version from bundled gem's version.rb
+        def versionFile = file("${gemDir}/lib/jopenssl/version.rb")
+        def versionContent = versionFile.text
+        def bcVersionMatcher = (versionContent =~ /BOUNCY_CASTLE_VERSION\s*=\s*'([^']+)'/)
+        if (!bcVersionMatcher.find()) {
+            throw new GradleException("Cannot parse BOUNCY_CASTLE_VERSION from ${versionFile}")
+        }
+        def bcVersion = bcVersionMatcher.group(1)
+        def gemVersion = (versionContent =~ /VERSION\s*=\s*'([^']+)'/)[0][1]
+        logger.lifecycle("Syncing stdlib BouncyCastle jars: using version ${bcVersion} from jruby-openssl ${gemVersion}")
+
+        // Replace stdlib BC jars with those from the bundled gem.
+        // We avoid deleting old version jars because on Windows they may still be locked
+        // by the JRuby process that ran installDefaultGems. Instead, we copy the new version
+        // jars alongside any existing ones. The jopenssl/load.rb uses BOUNCY_CASTLE_VERSION
+        // from version.rb to select which jars to load, so old jars are simply ignored at runtime.
+        def stdlibBcDir = file("${stdlibDir}/org/bouncycastle")
+        stdlibBcDir.mkdirs()
+
+        def gemBcDir = file("${gemDir}/lib/org/bouncycastle")
+        if (gemBcDir.exists()) {
+            def bcArtifacts = ["bcprov-jdk18on", "bcpkix-jdk18on", "bctls-jdk18on", "bcutil-jdk18on"]
+            bcArtifacts.each { artifact ->
+                def gemArtifactVersionDir = file("${gemBcDir}/${artifact}/${bcVersion}")
+                if (gemArtifactVersionDir.exists()) {
+                    def stdlibArtifactDir = file("${stdlibBcDir}/${artifact}")
+                    def targetDir = file("${stdlibArtifactDir}/${bcVersion}")
+                    targetDir.mkdirs()
+                    copy {
+                        from gemArtifactVersionDir
+                        into targetDir
+                    }
+                    // Best-effort cleanup of old version dirs (may fail on Windows due to file locks)
+                    if (stdlibArtifactDir.exists()) {
+                        stdlibArtifactDir.eachDir { versionDir ->
+                            if (versionDir.name != bcVersion) {
+                                try {
+                                    delete(versionDir)
+                                } catch (Exception e) {
+                                    logger.warn("Could not remove old BC jars at ${versionDir} (file may be locked): ${e.message}")
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        // Update stdlib's jopenssl/version.rb to match the bundled gem
+        def stdlibVersionFile = file("${stdlibDir}/jopenssl/version.rb")
+        if (stdlibVersionFile.exists()) {
+            stdlibVersionFile.text = versionContent
+        }
+
+        logger.lifecycle("Stdlib BouncyCastle jars synced to version ${bcVersion}")
+    }
 }
 
 tasks.register("installDevelopmentGems") {
diff --git a/lib/pluginmanager/util.rb b/lib/pluginmanager/util.rb
index e6710039db..06f3d9acb9 100644
--- a/lib/pluginmanager/util.rb
+++ b/lib/pluginmanager/util.rb
@@ -17,6 +17,7 @@
 
 require "rubygems/package"
 require "yaml"
+require "digest"
 
 module LogStash::PluginManager
   def self.load_aliases_definitions(path = File.expand_path('plugin_aliases.yml', __dir__))
diff --git a/rakelib/artifacts.rake b/rakelib/artifacts.rake
index 75dea58784..143dd6593f 100644
--- a/rakelib/artifacts.rake
+++ b/rakelib/artifacts.rake
@@ -119,6 +119,7 @@ namespace "artifact" do
     @exclude_paths << 'docker/data/logstash/env2yaml/**/*.java'
     @exclude_paths << 'docker/data/logstash/env2yaml/build.gradle'
     @exclude_paths << 'docker/data/logstash/env2yaml/settings.gradle'
+
     @exclude_paths.freeze
   end